Chemiluminescence immunoassay (CLIA) is a novel labeling immunoassay technique that combines a chemiluminescent or bioluminescent system with an immune response for the detection of trace antigens or antibodies. Chemiluminescence immunoassay is currently the most mainstream immunoassay technology in the world. It has the advantages of high sensitivity, wide detection range, short reaction time, fully automatic operation, good reproducibility, no pollution, and the like. It is an ultra-high sensitive micro-detection technology developed after radioimmunoassay, enzyme immunoassay, and fluorescence immunoassay. The principle of chemiluminescence is the light generated when the ground-state molecule absorbs the energy released in the chemical reaction to transition to the excited state, and the excited-state molecule returns to the ground state in a form of optical radiation. Chemiluminescence immunoassay is a combination of chemiluminescence and immunoassay, which combines the high sensitivity of chemiluminescence and the high selectivity of immunoassay.
In chemiluminescence immunoassays, luminescent substances commonly used include luminol, isoluminol, 3-(2-spiroadamantane)-4-methoxy-4-(3-phosphoryloxy)-phenyl-1,2-dioxetane disodium salt (abbreviated as AMPPD), terpyridine ruthenium, or acridine luminescent substance. Isoluminol, terpyridine ruthenium, and acridine luminescent substances can be used as a tracer molecule for direct labeling, and belongs to flash-type chemiluminescent substance. Luminol and AMPPD rely on peroxidase and alkaline phosphatase as tracer molecules for labeling, respectively, and belong to enzymatic luminescent chemiluminescent substances. The luminescence reaction of the acridine luminescent substance does not require a catalyst, and can be carried out in an alkaline environment, and the luminescence reaction is rapid, the background luminescence is low, and the signal-to-noise ratio is high. In addition, the luminescence reaction has few interference factors, good reagent stability, simple chemiluminescence system and low cost of the excitation liquid, and the acridine luminescent substance is an ideal chemiluminescent substance.
The conventional acridine-type fully automatic chemiluminescence system mainly uses hydrogen peroxide in combination with an acidic solution and an alkaline solution as a luminescence starting reagent, and some of that adds enhancers such as polyethylene glycol octyl phenyl ether (Triton X-100) and Tween 20 (Tween 20) to the luminescence starting reagent to enhance luminescence. However, the effect of enhancing the luminescence after the addition of the conventional enhancer is not obvious. In summary, the conventional acridine luminescent substance has a weak luminescence intensity.